Hydrogen cyanide is highly toxic, but a commercially important chemical compound having a wide variety of industrial uses. Hydrogen cyanide is produced commercially by contacting ammonia, excess hydrocarbon gas, and an oxidizing gas with a platinum-group-metal catalyst. The excess hydrocarbon gas is ignited, and the heat generated is sufficient to cause the endothermic reaction of ammonia and the remaining hydrocarbon gas to form hydrogen cyanide.
Shipment of hydrogen cyanide presents potential hazards. One way to avoid these potential hazards is to produce the product at the site where it is to be used. However this requires the installation of a large number of small production facilities. Such production facilities have in the past been expensive.
It is an objective of the present invention to provide a process for the production of HCN that can be operated on a relatively small scale but efficiently and at a low installation cost.
The present invention employs the use of induction heating of a platinum-group-metal catalyst to cause ammonia to react with hydrocarbon gas and form hydrogen cyanide. The reaction is endothermic, and by the use of induction heating the amount of energy used may be carefully regulated so that a minimum of energy is wasted.
The use of induction heating to heat catalyst to cause chemical reactions of various types is known; for example in Edward's U.S. Pat. No. 5,110,996 vinylidine fluoride is produced by the reaction of dichlorofluoromethane with methane, and the reaction tube contains a non-metallic packing material, and optionally a metallic catalyst--see column 3 line 5. Conventionally induction heating is carried out at frequencies of about 0.1 to 0.2 MHz.